Appendix T
Field Verification Protocol for Determining Reduction in Infiltration
Levels and Mechanical Ventilation Requirements for Site Built and
Mobile Homes with Verified Air Sealing
October 1, 2003
Scope: This Appendix describes the blower door test protocol for testing the air-leakage of site built
single-family houses and manufactured/mobile homes to determine the reduction in air infiltration
level achieved by air sealing measures. It also sets out the minimum mechanical ventilation system
requirements that must be met whenever house-tightening results in a house’s natural ACH is below
.45
1.0 TESTING PROTOCOL ..................................................................................................................... 2
1.1 When to Test: ................................................................................................................................. 2
1.2 House/Residence Preparation: ........................................................................................................ 2
1.3 Equipment Set-up: .......................................................................................................................... 2
1.4 Performing the Test: Perform the test using the following procedures: ........................................ 3
1.5 Computing Air Leakage Reduction: ............................................................................................... 3
1.6 Estimate Annual Energy Savings and C&R Discount Credit:........................................................ 4
2.0 - MECHANICAL VENTILATION REQUIREMENTS ........................................................................ 4
2.1 Mechanical Ventilation .................................................................................................................. 4
2.2 Unbalanced Non-Heat-Recovery Ventilation-Continuous Operation ............................................ 6
2.3 Balanced Flow Non-Heat Recovery Ventilation-Continuous Operation ....................................... 6
2.4 Air-to-Air Heat Exchangers ........................................................................................................... 6
2.5 Other Mechanical Ventilation Systems .......................................................................................... 7
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1.0
TESTING PROTOCOL
1.1
When to Test:
1.1.1
New construction Testing shall occur after everything is roughed-in/ installed that will penetrate the
building envelope (e.g., plumbing, electrical, HVAC, ventilation, combustion
appliances, etc.) and the air barrier has been installed.
1.1.2
Existing construction Testing shall occur immediately prior to the installation of any air leakage control
measures. Post-installation testing shall occur immediately following the installation
of air leakage control measures.
1.1.3
1.2
All testing will be done by Climate Crafters certfied contractors
House/Residence Preparation:
All single family houses and manufactured/mobile homes shall be checked before testing to
assure that following preparation measures have been completed.
1.2.1
Building envelope:
All windows and doors shall be properly closed, including pass-through wood-box
doors and pet doors. All interior doors shall be left open.
1.2.2
Ventilation openings:
All exhaust fan openings, vent openings, and intake-air vents with backdraft dampers
(e.g., dryer vents and kitchen, bathroom, utility room, whole-house, range vents, etc.)
shall NOT be sealed.
Exterior vent openings without backdraft dampers (e.g., some continuous ventilation
systems) shall be temporarily sealed for the test. Heat recovery ventilator supply
openings shall be sealed. Heat recovery ventilator exhaust openings should have
backdraft dampers and shall not be sealed.
1.2.3
Forced-air heating systems:
Supply and return registers shall NOT be sealed and the heating system shall be
turned off. HVAC ducts shall be tested with the envelope. Dampers in the outsideair supply duct into the return plenum shall be closed.
1.2.4
Combustion appliances:
All flue dampers, fireplace doors, and wood burning stove doors shall be closed, but
NOT sealed.
1.3
Equipment Set-up:
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The blower door equipment shall be set-up using the following procedure:
1.3.1
Gauge temperature
Keep the gauges at room temperature if possible. Cold temperatures may affect
gauge accuracy. This procedure is not required for digital guages
1.3.2.
Blower door
Install the blower-door assembly in a secure nanner.
1.4
1.5
1.3.3.
Set up the gauge assembly with the gauges plumb and level. This procedure is not
required for digital guages
1.3.4.
Attach a hose to the indoor pressure tap. Place the free end of the hose indoors away
from the fan airflow path at the approximate height of the fan centerline.
1.3.5.
Exercise the gauges by blowing and sucking on the hoses to drive the gauges over
their entire range six to eight times. Install the fan orifice plate, plug or seal all holes,
and adjust the gauges to zero. This procedure is not required for digital guages
1.3.6.
Start the fan and depressurize the house to check for anomalies in the building
envelope.
Performing the Test: Perform the test using the following procedures:
1.4.1.
Depressurize the house to 55 Pascals and reduce the pressure to 50 Pascals (0.205
inches of water).
1.4.2.
Tap the gauge to reduce stored spring energy from the gauge needle and wait for the
needle to stabilize before recording the readings. This procedure is not required for
digital guages
1.4.3
View the gauge from directly in front when taking a reading. Maintain a consistent
line of sight to avoid parallel errors or distortions from the gauge cover. This
procedure is not required for digital gauges.
1.4.4.
Increase the pressure again and then retest at 50 Pascals.
Computing Air Leakage Reduction:
1.5.1
Calculate the ACH @ 50 Pascals (ACH50pre) prior to installation of air sealing
measures and divide this value by 20 to estimate the average annual infiltration rate
(ACHavg).
1.5.2
Calculate the ACH @ 50 Pascals (ACH50post) after to installation of air sealing
measures and divide this value by 20 to estimate the average annual infiltration rate
(ACHavg).
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1.5.3
1.6
Subtract the value obtained in step 5.2 from that obtained in step 5.1 to determine the
reduction in annual infiltration rate achieved. Round this value to the nearest 0.1
ACH.
Estimate Annual Energy Savings and C&R Discount Credit:
1.6.1
To compute the annual energy savings multiply the estimated reduction in annual
infiltration rate times the homes floor area times the value in Table 1 for the
appropriate building type and climate zone.
Table 1 - Annual Energy Savings
(kWh/sq.ft./0.1 ACH change)
Building Type
Zone 1
Zone 2 Zone 3
Mobile/Manufactured Homes
0.5
0.7
0.8
Site Built Homes
0.2
0.3
0.4
1.6.2
To compute the C&R Discount Credit multiply the estimated annual energy savings
obtained in Step 6.1 times the value in Table 2 for the appropriate building type and
climate zone.
Table 2 – Conservation and Renewable Rate Discount
Credit
($/kWh saved)
Zon
Building Type
Zone 1
e2
$
$
Mobile/Manufactured Homes
0.39
0.39
$
$
Site Built Homes
0.50
0.50
Zone
3
$
0.39
$
0.50
2.0 - MECHANICAL VENTILATION REQUIREMENTS
2.1
Mechanical Ventilation
A mechanical ventilation system meeting either the requirements of 2.1.1, 2.2, 2.3 or 2.4 shall
be installed in all homes that have reductions that result in an ACH natural of less than .45 in
air leakage rates verified through this protocol.
2.1.1
Non-Heat-Recovery Ventilation - Intermittent Operation
2.1.1.1 A bathroom exhaust fan is controlled by both a manual switch, crank timer or
dehumidistat in the bathroom to provide spot ventilation AND a time clock
to provide whole-house ventilation when called for by the timer, Undercut
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doors, grilles, transoms, or other approved means provide fresh-air
circulation through the house to the bath fan shall be installed
2.1.1.2 Exhaust ducts shall be smooth metal and terminate outside the house at the
closest possible location. All connections shall be tight fitting and taped or
sealed, and backdraft dampers shall be provided.
2.1.1.3 The minimum exhaust airflow rates shall comply with either the performance
OR prescriptive paths listed below. Surface-mounted fans shall have a sone
rating of 1.5 or less, or other rating as approved by the Utility. Existing fans
that meet the minimum airflow rates are exempt from the sone rating
requirement.
2.1.1.3.1.
Performance Path: The minimum measured airflow capacity
shall be either 0.35 air-changes per hour (ACH) or those listed
below:
Number of
Bedrooms
1
2
3
4
Measured Exhaust
Flow
45 cfm
60 cfm
75 cfm
90 cfm
To calculate the ACH for a fan with a MEASURED airflow of
45cfm multiply by 60 to obtain the airflow per hour (45 X 60 =
2700 cfh) and divide by the volume of the heated space.
2.1.1.3.2
Prescriptive Path: Ventilation systems that do not meet the
performance path shall provide 0.35 ACH based upon the rated
fan flow minus 15 cfm or use the rated fan flows in the following
table:
Number of
Bedrooms
1
2
3
4
Rated Fan Flow
70 cfm
85 cfm
100 cfm
115 cfm
To calculate ACH based on the RATED airflow, subtract 15
cfm, multiply by 60, and divide by the volume of the heated
space.
2.1.1.4 The fan shall have both automatic and manual controls. Automatic controls
shall include a time clock or cycle timers with a minimum of 2 on-periods
per day, a manual control switch to lot the occupant turn the fan on or off,
and be set to operate a minimum of 8 hours per day.
2.1.1.5 The ventilation fan shall be wired to both the manual spot-ventilation switch
in the bathroom and to a time clock.
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2.2
2.3
Unbalanced Non-Heat-Recovery Ventilation-Continuous Operation
2.2.1
This system uses a continuously-operating fan to exhaust air at a minimum rate of
25 cfm for the kitchen, and 20 cfm for each bathroom, with a maximum rate of 0.5
ACH. One fan exhausting from the kitchen and each bathroom also provides spot
ventilation. An integrated spot and whole-house fan is acceptable if spot ventilation
is also provided for the kitchen and for the bathrooms.
2.2.2
The exhaust-air pickup in the kitchen shall not be over the kitchen range.
2.2.3
If the exhaust flow from each kitchen and bathroom is not measured,
the rated fan capacity shall exceed the required flow rate by a minimum of 15 cfm.
2.2.4
The continuous ventilation fan(s) shall be wired to an existing circuit or to the
electrical service panel.
2.2.5
The outside-air inlet and source requirements shall be the same as Sections 2.1.4.6,
2.1.4.7 and 2.1.4.8.
Balanced Flow Non-Heat Recovery Ventilation-Continuous Operation
2.3.1
Balanced flow non-heat-recovery air exchange units shall:
2.3.1.1 have fans capable of providing the intake and exhaust airflow rates in
section 2.1.1.3 at 0-25 inches of water gauge as determined by HVI 916 (July
1993);
2.3.1.2 provide complete isolation of the intake and exhaust air;
2.3.1.3 have UL approval of all electrical components;
2.3.1.4 have outside-air inlets in all living areas and bedrooms, positioned so-as-to
avoid drafts; and
2.3.1.5 be installed according to the manufacturers instructions.
2.4
Air-to-Air Heat Exchangers
2.4.1
Air-to-air heat exchangers shall:
2.4.1.1 Provide the ventilation rates in Section 2.1.1.3;
2.4.1.2 have a minimum sensible heat recovery efficiency of 65 percent at 117 cfm
and 32F for homes larger than 1300 ft.2 and 55 percent at 64 cfm and 32F
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for houses of 1300 ft2 or less as certified by the Home Ventilation Institute
(HVI);
2.4.1.3 have a filter on the upstream side of the heat exchanger in both the intake and
exhaust airstreams;
2.4.1.4 provide protection against ice buildup that does not disable the unit during
freezing weather; and
2.4.1.5. be installed according to manufacturer's instructions.
2.5
Other Mechanical Ventilation Systems
2.5.1
2.6
Other mechanical ventilation systems meeting the Site Built or Manufactured
Housing Super Good Cents specifications may be used if approved by Bonneville.
Combustion Appliance Zone Pressure Test
2.6.1 Forced air system operation shall not de-pressurize a combustion appliance zone
by more than 3 Pascals with reference to outside. As a further safety precaution, the
Climate Crafters Standard also requires the installation of a UL listed Carbon Monoxide
whenever combustion appliances are within the conditioned space of the home.
2.6.2 Application: This test is required for Climate Crafters Certification whenever a
combustion appliance is present within a building. A Combustion Appliance Zone (CAZ)
is any zone in the house that contains a combustion appliance. CAZs need not be heated.
An attached garage or unheated basement with a combustion-fired furnace or water
heater is a CAZ. A zone with a sealed combustion appliance that has an isolated
combustion path preventing mixing of room air and combustion air is not considered a
CAZ. The test measures the magnitude of any air handler induced pressures that may
cause dangerous back drafting of combustion appliances. Door closures that isolate
supply and return sides of the system may also induce negative pressure within a
combustion appliance zone. In retrofit situations, the test should be done both before and
after sealing.
2.6.3 Performing the Test
2.6.3.1 The house should be set up for normal heating season operation with all exterior
doors and windows closed.
2.6.3.2 Turn off all exhaust devices including clothes dryer, bathroom fans, kitchen
fan, central vacuum, and whole house ventilation systems.
2.6.3.3 Open all return and supply registers.
2.6.3.4 Turn off combustion devices so that they will not operate during the test
(except furnace if air handler will not operate at high speed without firing).
2.6.3.5 Remove furnace filters.
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2.6.3.6 Shut off any outside ventilation air to the duct system if it can normally be shut
off during air handler operation.
2.6.3.7 Close manual flue dampers
2.6.3.8 Interior Door Set Up:
2.6.3.9 Turn air handler fan on highest speed
2.6.3.11 Using the manometer, check the pressure in each zone isolated behind a closed
door WRT to the CAZ.
If the zone behind the closed door is positive WRT to the CAZ, leave the door
closed for the test.
If the zone behind the closed door is negative WRT to the CAZ, open the door for
the test.
2.7.0 Record the CAZ pressure WRT to outside. This is the gross depressurization
2.7.1 Turn off air handler and record pressure with CAZ WRT to outside. This is the
baseline pressure
2.7.2 Subtract the baseline pressure from the gross depressurization pressure. This is the
net handler effect.
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